Beckley, then 26, then sought medical help and another 13 worms were extracted. The local doctors, however, did not know what to make of the infection and passed the case on to the Centers for Disease Control and Prevention in Atlanta.

According to the Washington Post, scientists at a special laboratory that deals with parasitic diseases determined that she had been infected by a species of eye worm often found in cattle but rarely seen in humans.

“We never expected to see this particular species in a human,” medical parasitologist Richard Bradbury told the paper. “Until now, this type of worm, Thelazia gulosa, had only been found in cattle.”

Abby Beckley is the first known person to have contracted Thelazia gulosa, an eye worm usually found in cattle.

KGW.com

And that’s when they put two and two together — it turned out that in the weeks before her infection, Beckley had been walking through cattle fields in southern Oregon. It was very possible, she told the Post, that a fly landed on her eye and infected her.

Bradbury then started digging back in medical records and found references to the Thelazia worm infecting humans.

"There's only ever been in the history of the published literature 11 cases of in America, so it's very rare and unusual," Bradbury told CBS News.

Fortunately, the worms did not cause permanent harm. Rather than burrowing into the eye, they are mostly content to feed on tears and other secretions. However, they can cause inflammation if not discovered early.

“We were able to tell her this was very localized,” said Erin Bonura, an infectious disease specialist who treated her in Oregon. “She was worried they would crawl into her brain,” she told the Post.